In state of the art jewelry, rings have a constant thickness shank portion. When placed on a conventional ring sizer, a pressure roller will squeeze the shank and cause it to become thinner and lengthen slightly. However, upon initial contact with the shank the conventional ring sizer will force a dent into the shank. It has been found that each time the shank is dented (as the pressure roller is forced to increase pressure on the ring shank) these dents are stretched out during the rolling process, causing flat portions on the shank. Once the ring is the appropriate size, the jeweler must then polish and grind the shank to remove these unsightly flat spots, and to polish the rolled surface of the stretched shank.
Typically, the flat inner surface of the shank of the ring meets the arcuate circumferal surface of the shank at a sharp edge. This edge is made even sharper by conventional ring sizers. This sharp edge will also show the stretch marks which occur during the rolling in the sizing of the ring. Thus, the jeweler must also grind and polish the ring shank to remove these sharp edges and stretch marks after sizing.
Most department stores do not sell silver rings because of the expense in sending the rings out to be accurately sized. It can be seen that conventional rings and ring sizers require additional expensive equipment in order to grind and polish the rings after the conventional sizing process. The cost of silver is not high enough to make it economically feasible to send the rings out to be sized, nor is the cost of silver low enough to allow the store to keep a stock of all sizes on hand. As discussed above, conventional ring sizing equipment is quite expensive and is not typically easily used by unskilled labor. Thus, silver rings have not been a viable product for department store sale.
Similarly, gold rings are sent out for sizing because of the cost of obtaining and maintaining expensive sizing equipment and accessory grinding and polishing equipment. Skilled labor is also necessary. While the cost of gold makes it economically feasible to send these jobs out, it would be desirable to provide this service in the store.
It is therefore a principal object of this invention to provide an improved method and apparatus for enlarging rings.
Another object is to provide a ring sizer which is simple to operate.
Still another object of the invention is to provide a ring with a variable thickness shank which enhances its ability to be easily sized using the apparatus and method of this invention.
A further object is to provide a ring sizer which simultaneously polishes the ring shank as it enlarges the ring.
Yet another object is to provide a ring with a shank which will eliminate sharp edges or stretch marks upon sizing using the apparatus and method of this invention.
Still another object of the present invention is to provide an improved ring sizer which is economical to manufacture, durable in use and refined in appearance.
These and other objects of the present invention will be apparent to those skilled in the art.